Over the past decade, there has been increasing interest in the development of miniaturized chemical analysis systems using micro-electromechanical (MEMS) technology. Until more recently, the prior art in MEMS technology has included UV absorbance and electro-chemi-luminescence for on-chip detection. These optical methods are not viable for detection of many biomolecules. A viable commercial product should be able to process/analyze a wide range of samples.
Mass spectrometers (“MS”) are one type of widely used macroscopic instrument for the analysis of biomolecular structures such as proteins, carbohydrates, lipids and polynucleotides. MS is widely used due to its ability to analyze large proteins and peptides. MS also has high sensitivity, e.g., as high as 10−12 moles.
Much experimentation has focused on an on-chip interface that has the advantage of directly coupling a MEMS electrospray nozzle to an MS inlet.